In such an installation, the module for varying the speed of the motor must meet a certain number of constraints, particularly as regards the removal of the heat energy generated by the module, as well as relating to electromagnetic interference. For example, the use of a module of the pulse-width modulation type employs power-pulse switching operations which generate electromagnetic radiation, which is transported particularly by the connecting wires, downstream to the motor and upstream to the control electronics of the module and the power supply wires. The EMI electromagnetic interference standards limit the allowed radiation, which means that the modules, and particularly the modules with pulse-width modulation PWM, comprise filters, as does the motor.
It is certainly possible, as the U.S. Pat. No. 5,070,267 moreover teaches, to house the control module entirely within the motor, but this means designing the motor specifically, and there can the before be no question in such a case of using already existing standard motors. Moreover, implementing such integration poses not inconsiderable problems of cost.
It has been proposed, in addition, to house the module outside the motor, but this is accompanied by the existence of linking wires between the module and the motor which do not ease the solving of the problem of the electromagnetic interference EMI.
This EMI interference is generated by radiation from the linking wires which constitute antennae and/or from the power-supply cabling of the module, which can disturb electronic apparatus (car radio, etc.).
The object of the present invention is to provide a heating and/or air-conditioning installation which makes it possible at least partly to solve the abovementioned problems.